The present invention relates in general to preparations for topical skin treatment and, more particularly, to preparations comprising silicone matrices and hydrophilic carriers that provide sustained release of active agents.
Silicones are compounds based on alkylsiloxane or organosiloxane chemistry and include polydimethylsiloxane materials that have been used as excipients and process aids in pharmaceutical applications. Some of these materials have attained the status of pharmacopoeial compounds. Known in the art is the use of such silicone compounds in controlled drug delivery systems, especially in applications where the association of specific properties is critical to meet the requirements of product design, i.e., biocompatibility and versatility. New long lasting drug delivery applications including implant, insert, mucoadhesive, transdermal, and topical forms draw on the unique and intrinsic properties of silicone. These delivery systems allow controlled release of active molecules with biologically appropriate kinetics to a targeted area, and prevent the adverse effects, such as peak dosages, low compliance, and drug degradation, commonly observed with traditional oral and parenteral medication.
Transdermal drug delivery systems consist of drug containing adhesive patches, which adhere to intact skin up to 7 days. The patch design controls the release of the active agent, which is then carried through the organism by the circulatory system for a systemic activity. Using the skin as an entry point, the topical forms, which consist of an adhesive plaster or a film-forming and substantive material (e.g., cream or gel), are used for local treatment (muscle or skin disease). However, these transdermal drug delivery systems have not been incorporated into topical dressing applications such as wound dressings and ointments, wherein a biochemical agent dispersed within a silicone matrix is released onto skin or a wound to accelerate healing.
Accordingly, the need remains in the relevant art for preparations that take advantage of the beneficial properties of silicone, and can provide sustained release of active agents.